1. Statement of the Technical Field
The inventive arrangements relate to communication systems, and more particularly to systems and methods for providing call/connection establishment in cellular networks.
2. Description of the Related Art
There are various cellular networks known in the art. Such cellular networks include a Wideband Code Division Multiple Access (WCDMA) based network, a Long Term Evolution (LTE) based network, an LTE Advanced based network and various other networks that offer a state of high readiness with a shared/common channel. Each of these cellular networks comprises a plurality of communication devices and network equipment configured to facilitate communications between the communication devices. Each cellular network often provides a PTT service to a PTT service subscriber using a communication device. The PTT service is an instant service by which the PTT service subscriber is able to immediately talk to one or more other PTT service subscribers by pushing a PTT button of the communication device.
A WCDMA based cellular network typically supports various modes of communication, such as a shared channel mode and a dedicated channel mode. In the shared channel mode, data is communicated between a calling communication device and a called communication device at a first data transfer rate (e.g., 16 Kilo-bits per second or 32 Kilo-bits per second) over a shared channel in an air interface. The phrase “shared channel”, as used herein, refers to a channel that carries data associated with a plurality of communication devices. In the dedicated channel mode, data is communicated between the calling communication device and the called communication device at a second data transfer rate over a dedicated channel. The phrase “dedicated channel”, as used herein, refers to a channel that carries data associated with only one (1) communication device. The second data rate (e.g., 2-40 Mega-bits per second) is greater than the first data transfer rate.
During operation, the communication devices and network equipment dynamically switch between their shared channel modes and their dedicated channel modes based on one or more existing or predicted conditions of a connection established therebetween. These conditions can include, but are not limited to, the amount of data to be communicated to and from a communication device. For example, if the amount of data to be communicated from a calling communication device exceeds a particular threshold value or data rate, then the calling communication device and associated network equipment transition from their shared channel mode to their dedicated channel mode. Similarly, if the amount of data to be communicated to a called communication device exceeds a particular threshold value or data rate, then the called communication device and associated network equipment transitions from their shared channel mode to their dedicated channel mode.
Notably, a calling communication device will not transmit voice packets while it is transitioning from its shared channel mode to its dedicated channel mode. Likewise, a called communication device will not receive voice packets when it is transitioning from its shared channel mode to its dedicated channel mode. In effect, an interruption in speech communications occurs. This interruption in speech communications is undesirable from the point of view of speech quality.
In view of the forgoing, there is a need for an improved method for reducing the delay in setting up calls. In this regard, there is a need for an improved method for dynamically switching between the shared channel modes and the dedicated channel modes. This improved method should facilitate the provision of a communication system with an upswitch or communication mode switch time that is decreased as compared to that of conventional systems (such as those described above).